Implantable medical devices (IMDs) are commonly used to provide treatment to patients. Implantable medical devices can include cardiac rhythm management devices and neurological stimulation devices, amongst others. Some types of implantable medical devices deliver electrical stimuli to a target tissue via a lead wire (“stimulation lead”) or catheter having one or more electrodes disposed in or about the target tissue.
In many scenarios, implantable medical devices are configured to sense electrical activity in vivo. By way of example, cardiac rhythm management devices frequently sense electrical activity of cardiac tissue in order to gather information about cardiac rhythm and the effect of therapeutic electrical stimulation.
Some implantable medical devices include features directed to automating the process of setting device parameters. By way of example, some implantable medical devices include what is known as an automatic threshold measurement test. This test automatically determines the minimum amplitude of electrical stimulation needed to cause a given chamber of the heart to contract. At a high level, this test involves stimulating at successively lower amplitudes and monitoring for contraction (an evoked response) until the amplitude becomes so low that contraction is no longer achieved in response to the stimulation. However, noise can limit the accuracy of such testing.